Method of cooling devices

ABSTRACT

It is intended to extend life spans of devices as a whole by reducing differences of temperatures of devices which are mounted on a printed circuit board by plural number without increasing the volume of cooling gas. In the method of cooling multiple driver&#39;s ICs which are continuously mounted on a printed circuit board, the devices having heat sinks provided with multiple radiating fins disposed thereon in parallel with one another, each radiating fin is positioned relative to a blowing direction of cooling gas at a given inclination angle θ.

FIELD OF THE INVENTION

[0001] The invention relates to a method of cooing devices, particularly to a technique for cooling multiple devices mounted linearly on a printed circuit board.

BACKGROUND OF THE INVENTION

[0002] In a case where many electronic devices each having a large power capacity are used, each device is provided with a heat sink and mounted on a printed circuit board in a given interval. In such a case, if sufficient radiating performance is not obtained by the heat sink, cooling gas is blown out toward each heat sink using a fan and the like, thereby forcibly cooling each heat sink.

[0003] However, according to the conventional forcible cooling method, it is difficult to cool multiple devices uniformly, which causes a problem that devices which were not sufficiently cooled are deteriorated earlier than devices which were sufficiently cooled. This is caused by the fact that a sufficient amount of gas is not blown out toward the heat sinks (devices) positioned downstream relative to cooling gas. It is considered as a simple solving means to increase the volume of cooling gas by rendering a fan large-sized, which however invites a subsidiary issue such as the increase of power consumption and noise.

SUMMARY OF THE INVENTION

[0004] The invention has been made to solve the foregoing problems and it is an object of the invention to extend life spans of devices as a whole, which devices are mounted on a printed circuit board by plural number, by reducing temperature differences between the devices without increasing the volume of cooling gas.

[0005] Th achieve the above object, a method of cooling devices continuously mounted on a printed circuit board, the devices having heat sinks provided with multiple radiating fins disposed thereon in parallel with one another according to the invention adopts first means, wherein each radiating fin is positioned relative to a blowing direction of cooling gas at a given inclination angle θ.

[0006] The invention adopts second means, wherein the devices in the first means are ICs for a driver (hereinafter referred to as driver's ICs) used in a test head of a semiconductor integrated circuit testing device for outputting testing signals to devices under test.

[0007] The invention adopts third means, wherein the driver's ICs in the second means are mounted in a row on a printed circuit board and cooling gas is blown out from a given direction along the surface of the printed circuit board.

[0008] The invention adopts fourth means, wherein the heat sinks are mounted onto the devices by a heat conductive adhesive.

[0009] The invention adopts fifth means, wherein the cooling gas according to any of the first and fourth is air.

[0010] The invention adopts sixth means, wherein the inclination angle θ according to any of first to fifth means is set at 30 degrees.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011]FIG. 1 is a view showing an arrangement of devices in accordance with a preferred embodiment of the invention.

[0012]FIG. 2 is a view showing temperature characteristics of respective driver's ICs in the case where an inclination angle θ is set at 30 degrees

PREFERRED EMBODIMENT OF THE INVENTION

[0013] A method of cooling devices according to a preferred embodiment of the invention is now described with reference to the attached drawings. The preferred embodiment is a case where the invention is applied to a method of cooling driver's ICs to be mounted in a test head of a semiconductor integrated circuit testing device. Multiple driver's ICs are mounted inside a test head for outputting test signals to respective terminals of DUTs which are objects to be tested.

[0014]FIG. 1 is a view showing an arrangement of devices in accordance with the preferred embodiment. In FIG. 1, depicted by 1 is a printed circuit board, 2A to 2H are heat sinks, 3 is radiating fins, 4A to 4H are driver's ICs and each A is a blowing direction of cooling air (cooling gas).

[0015] The

[0016] printed circuit board 1 is formed rectangular as shown in FIG. 1 and multiple driver's ICs 4A to 4H having heat sinks 2A to 2H attached thereto are mounted in a row on the printed circuit board 1.

[0017] The heat sinks 2A to 2H have respectively multiple radiating fins 3 which are arranged in parallel with one another, and they are attached to the upper surfaces of the driver's ICs 4A to 4H via silicon glass or heat conductive adhesive. The heat sinks 2A to 2H and the driver's ICs 4A to 4H are in a tight heat connected state using silicon glass or heat conductive adhesive set forth above.

[0018] The heat sinks 2A to 2H are attached to the driver's ICs 4A to 4H while they are set in posture to be directed to each blowing direction A of cooling gas at an inclination angle θ relative to the radiating fins 3. The setting of postures of the heat sinks 2A to 2H relative to the blowing direction A of the cooling gas is an eminent feature of the invention.

[0019] The radiating fins 3 are formed, as well known, on the heat sinks 2A to 2H as protrusions which are arranged in parallel with one another in a given interval and they efficiently radiates heat generated in the driver's ICs 4A to 4H. The driver's ICs 4A to 4H are provided for outputting test signals (pattern signals) to respective terminals of the DUTs and have relatively large heating amount when they are operated. Accordingly, the heat sinks 2A to 2H have to be attached to the driver's ICs 4A to 4H for operating the driver's ICs 4A to 4H with a prescribed performance.

[0020] Each blowing direction A of cooing air is set to conform to the arranging direction of the driver's ICs 4A to 4H which are mounted in a row on the printed circuit board 1, namely, set in parallel with the arranging direction of the driver's ICs 4A to 4H. There is provided a fan beside the printed circuit board 1 for blowing out cooling air toward the driver's ICs 4A to 4H. By the operation of the fan, the cooling air is blown from the direction parallel with the arranging direction of the driver's ICs 4A to 4H toward the driver's ICs 4A to 4H along the surface of the printed circuit board 1.

[0021] According to the preferred embodiment of the invention, since the direction of the radiating fins 3 is inclined relative to each blowing directions A of cooling air at the inclination angle θ, the cooling air passes through the radiating fins 3 of the heat sinks 2A to 2H relatively uniformly That is, the cooling air removes heat uniformly from the heat sinks 2A to 2H compared with a case where the radiating fins 3 of the heat sinks 2A to 2H are all set in parallel with each blowing direction of cooling air so that the temperatures of the driver's ICs 4A to 4H are made uniform.

[0022]FIG. 2 shows temperature characteristics of respective driver's ICs wherein the measured values of temperatures of the driver's ICs 4A to 4H in the case where the inclination angle θ is set at 30 degrees are compared with those of the prior art. In FIG. 2, T1 represents temperature characteristics of the preferred embodiment, and T2 represents temperature characteristics of the prior art. Although the difference between the maximum temperature and the minimum temperature of the driver's ICs 4A to 4H is 20 degrees according to the preferred embodiment, while it is 29 degrees in the prior art. That is, since the increase of the temperatures of the driver's ICs (e.g. driver's ICs 4E to 4H) which are positioned more downstream relative to the cooling air is restrained, the difference between the maximum temperature and the minimum temperature according to the preferred embodiment is smaller than the prior art by 9 degrees.

[0023] Although the preferred embodiment is applied to the cooling of the driver's ICs 4A to 4H to be mounted inside the test head, the scope of application of the invention is not limited to this preferred embodiment. The invention can be applied to the cooling of various deices if they are continuously mounted in a printed circuit board in a state where the heat sinks are attached to the devices. Further, the devices may be mounted on a board other than the printed circuit board.

[0024] As mentioned in detail above, the cooling gas can strike more uniformly against the respective radiating fins of the heat sinks of the devices without increasing the volume of air. Accordingly, the respective devices can be maintained at a more uniform temperature, and hence electric performance of each device is improved and life span of each device is extended. 

What is claimed is:
 1. A method of cooling devices continuously mounted on a printed circuit board, the devices having heat sinks provided with multiple radiating fins disposed thereon in parallel with one another, wherein each radiating fin is positioned relative to a blowing direction of cooling gas at a given inclination angle θ.
 2. The method of cooling devices according to claim 1, wherein the devices are driver's ICs used in a test head of a semiconductor integrated circuit testing device for outputting testing signals to devices under test.
 3. The method of cooling devices according to claim 2, wherein the driver's ICs are mounted in a row on a printed circuit board and cooling gas is blown out from a given direction along the surface of the printed circuit board.
 4. The method of cooling devices according to claim 1, wherein the heat sinks are mounted onto the devices by a heat conductive adhesive.
 5. The method of cooling devices according to claim 1, wherein the cooling gas is air.
 6. The method of cooling devices according to claim 1, wherein the inclination angle θ is set at 30 degrees.
 7. The method of cooling devices according to claim 2, wherein the heat sinks are mounted onto the devices by a heat conductive adhesive.
 8. The method of cooling devices according to claim 3, wherein the heat sinks are mounted onto the devices by a heat conductive adhesive.
 9. The method of cooling devices according to claim 2, wherein the cooling gas is air.
 10. The method of cooling devices according to claim 3, wherein the cooling gas is air.
 11. The method of cooling devices according to claim 4, wherein the cooling gas is air.
 12. The method of cooling devices according to claim 7, wherein the cooling gas is air.
 13. The method of cooling devices according to claim 8, wherein the cooling gas is air.
 14. The method of cooling devices according to claim 2, wherein the inclination angle θ is set at 30 degrees.
 15. The method of cooling devices according to claim 3, wherein the inclination angle θ is set at 30 degrees.
 16. The method of cooling devices according to claim 4, wherein the inclination angle θ is set at 30 degrees.
 17. The method of cooling devices according to claim 5, wherein the inclination angle θ is set at 30 degrees. 